Project Summary/Abstract Background. The ongoing COVID-19 public health crisis is significantly impacting older Americans who are at higher risk for severe illness from novel coronavirus infection. The implementation of shelter-in-place and social distancing, though an essential step in reducing transmission of the virus, has imposed unintended personal life hurdles and major social constraints on cognitively impaired older adults. Many of these individuals are dependent on community-based services for care and support and therefore face great challenges to performing essential social activities, including attending community-based exercise classes. Given that the signs of the outbreak abating are still vague and that there is the likelihood of new outbreak this winter, the continued enforced societal isolation will exacerbate sedentary behaviors in a population with already low levels of physical activity and poor physical and mental health outcomes. Objectives. This application requests Administrative Supplement to support the development and testing of an Internet-based exercise intervention (Tai Ji Quan Moving to Improve Brain Health [TJQMIBH]) using real-time videoconferencing for older adults with mild cognitive impairment (MCI). The proposed work aligns with the scope of our parent project (AG059546), which is designed to evaluate the efficacy of an in-person, group- based, cognitive-motor-integrated Tai Ji Quan intervention for this vulnerable and at-risk population. The funds from this Administrative Supplement will support research work related to the following four specific aims: Specific Aim 1: to transform the in-person TJQMIBH intervention protocol into a deliverable online class protocol; Specific Aim 2: to pilot test the online TJQMIBH virtual class delivery protocol in older adults with MCI; Specific Aim 3: To develop effective and protected online assessment and data ascertainment procedures encompassing the cognitive and physical performance measures; and Specific Aim 4: to conduct a randomized controlled trial comparing the effectiveness of the virtual TJQMIBH intervention with a stretching exercise control group among older adults with MCI. Significance and Impact. Shelter-in-place and social- distancing policies in response to COVID-19 have left older adults with cognitive impairment with few or no opportunities to continue physical activity in their community. Evidence suggests that limited or no physical activity may lead to an increased risk and potential worsening of chronic health conditions for this at-risk population. Meanwhile, there are few Internet-based exercise programs available to keep older adults active and healthy in the highly contagious COVID-19 environment. Our project addresses this urgent public health need by developing and delivering a virtual exercise program at home through the Internet. If successful, the outcome from this project will exert a sustained, powerful influence on the field of disease prevention by providing a safe, accessible, and effective exercise intervention for older adults with cognitive impairment that can be implemented both under current extreme conditions and in the aftermath of the COVID-19 pandemic.